CN106061616B

CN106061616B - Long term storage of waste by adsorption with high surface area materials

Info

Publication number: CN106061616B
Application number: CN201580012149.4A
Authority: CN
Inventors: J·W·帕滕
Original assignee: Red Leaf Resources Inc
Current assignee: Red Leaf Resources Inc
Priority date: 2014-01-28
Filing date: 2015-01-22
Publication date: 2020-09-25
Anticipated expiration: 2035-01-22
Also published as: WO2015116471A1; US9630225B2; AU2015211293B2; AU2015211293A1; CN106061616A; US20150209847A1

Abstract

A system and method for long term storage of waste is provided that may include a comminuted material (100) having a high surface area. The comminuted material (100) can include particles of treated hydrocarbonaceous material from which hydrocarbon products have been derived. The comminuted material (100) can be contacted with a flowable waste material such that the flowable waste material is retained in the comminuted material (100). This flowable waste is some material other than the hydrocarbon product obtained from the hydrocarbonaceous material. An encapsulation barrier (105) may surround the comminuted material (100) and provide an additional means of preventing the flowable waste material from escaping.

Description

Long term storage of waste by adsorption with high surface area materials

Related patent application

This patent application claims priority to U.S. provisional patent application No.61/932,582 entitled "Long Term Storage of Waste by Adsorption with High surface area Materials" (Long Term Storage of water Using Adsorption by High surface area Materials) filed on 28/1/2014, which is incorporated herein by reference.

Technical Field

The present invention relates to systems and methods for long term storage of flowable waste (e.g., hazardous waste) in a body of high surface area material. The present invention therefore relates generally to the technical fields of waste management, geology, material science and hydrodynamics.

Background

As more and more unwanted waste is produced around the world, waste disposal becomes an increasingly challenging problem. In particular hazardous waste disposal may involve complex and expensive measures to destroy or otherwise safely contain the hazardous waste. If the disposal method does not adequately manage the hazardous waste, the hazardous waste can escape into the surrounding environment and cause damage to plant and animal life, contaminate groundwater, and possibly other damage. Measures are often taken to immobilize the hazardous waste to prevent it from escaping into the environment. Various methods have been developed including enclosing the waste in hardened materials (e.g., cement, resin, or glass), injecting the waste into subterranean formation fractures, and storing the waste in landfills that may be equipped with leak-proof liners and detection systems. However, various challenges remain in terms of stability, durability, reliability, and economy of disposal sites, among others.

Disclosure of Invention

A system for long term storage of waste may include a comminuted material having a high surface area. The comminuted material can include particles of treated hydrocarbonaceous material from which hydrocarbonaceous products have been derived. The flowable waste material may be retained in the comminuted material. This flowable waste material is a material other than the hydrocarbon product obtained from the hydrocarbonaceous material. The encapsulation barrier may wrap the comminuted material.

Further, the method for storing flowable waste material may include contacting a substantially stationary body of comminuted material with the flowable waste material. The comminuted material can have a high surface area. The comminuted material can also include particles of treated hydrocarbonaceous material from which hydrocarbonaceous products have been derived. Finally, the comminuted material can be wrapped by a packaging barrier.

There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. Other features of the present invention will become more fully apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings and claims, or may be learned by the practice of the invention.

Drawings

Figure 1 is a cross section of a body of comminuted material wrapped by an encapsulation barrier according to one embodiment of the invention.

Figure 2 is a cross-section of a particulate of comminuted material having flowable waste material retained therein according to one embodiment of the invention.

Fig. 3 is a flow diagram of a method for storing flowable waste material according to one embodiment of the invention.

It is noted that the drawings are only examples of several embodiments of the invention and are not intended to limit the scope of the invention thereby. Moreover, the drawings are not generally to scale, but are drawn for convenience and clarity in illustrating various aspects of the invention.

Detailed Description

While these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, it should be understood that other embodiments may be realized and that various changes to the invention may be made without departing from the spirit and scope of the present invention. Thus, the following more detailed description of the embodiments of the present invention is not intended to limit the scope of the invention, as claimed, but is presented for purposes of illustration only and not limitation to describe the features and characteristics of the present invention, set forth the best mode of operation of the invention, and to sufficiently enable one skilled in the art to practice the invention. The scope of the invention is therefore intended to be limited solely by the appended claims.

Definition of

In describing and claiming the present invention, the following terminology will be used. The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a wall" includes reference to one or more of such structures, reference to "a waste material" includes reference to one or more of such materials, and "a contacting step" refers to one or more of such steps.

As used herein, "size reduction" refers to breaking structures or larger agglomerates into smaller pieces, for example, pieces typically less than about 2 feet in diameter. The comminuted agglomerates may be rubblized or otherwise broken into pieces using any number of techniques, including crushing, detonation, etc.

As used herein, "raw earthen material" refers to natural materials recovered from soil with only mechanical deformation, such as, but not limited to, swelling clays (e.g., bentonite, montmorillonite, kaolinite, illite, chlorite, vermiculite, etc.), gravel, rock, compacted fill, soil, and the like. For example, gravel may be combined with cement to form concrete. Often, clay amended soil can combine with water to form a hydrated layer that acts as a fluid barrier. In contrast, spent oil shale can be used in conjunction with the raw earth materials used in the walls of the encapsulation barrier, but not as the raw earth materials as used herein, because the pretreatment converts the embedded kerogen to hydrocarbon products.

As used herein, "flowable waste" refers to a material that is capable of flowing into a high surface area material under given conditions. The flowable waste may comprise a liquid, a gas, fine particles, a vapor, or a combination thereof. As used herein, "hazardous material" or "hazardous waste" includes any material that is capable of causing harm to animals, humans, or the environment, and exhibits one or more of the following characteristics: flammability, reactivity, corrosiveness, toxicity, or radioactivity. The environmental protection agency defines a number of hazardous wastes in 40 c.f.r.261 (7 months and 1 day 2012). However, any material that exhibits such characteristics to a degree that is not suitable for a given application or environment may be considered detrimental. For example, hazardous materials may also include radioactive materials, such as nuclear waste or related process materials, which are class a, class B or class C waste.

As used herein, "hydrocarbonaceous material" refers to a material comprising hydrocarbons from which hydrocarbon products can be extracted or derived. For example, liquid hydrocarbons may be extracted directly from the material, extracted by solvent extraction, directly vaporized, or otherwise liberated. However, many hydrocarbonaceous materials contain hydrocarbons, kerogen and/or bitumen, which are converted by heating and pyrolysis into higher quality hydrocarbon products, including oil and gas products. Hydrocarbonaceous materials can include, but are not limited to, oil shale, tar sands, coal, lignite, bitumen, peat, biomass, and other organic-rich rocks.

As used herein, "treated hydrocarbonaceous material" refers to hydrocarbon-containing material from which hydrocarbon products have been extracted or derived. For example, liquid hydrocarbons may be extracted directly from the material, extracted by solvent extraction, distilled directly, or otherwise extracted. However, many hydrocarbonaceous materials contain kerogen or bitumen, which is converted to hydrocarbons by heating and pyrolysis. Hydrocarbonaceous materials can include, but are not limited to, oil shale, tar sands, coal, lignite, bitumen, peat, biomass, and other organic-rich rocks. Such treated hydrocarbonaceous materials can optionally be mixed with other materials, such as rocks, cements, resins, other earthen materials, surfactants, binders, enzymes, biologically derived fillers, biological agents, inorganic agents, precursors, salts, and/or man-made materials.

As used herein, "producing" refers to the condition of moving or perturbing material from an initial formation or geographic location to a different, second location. Typically, mined material may be produced by rubblizing, crushing, detonation or otherwise removing material from the native formation for further use or processing.

As used herein, "retention capacity" refers to the amount of flowable waste material that can remain substantially stationary within the body of comminuted material. The retention capacity may depend on a number of factors, such as the surface area of the comminuted material, the porosity of the comminuted material, void spaces in the comminuted material, the amount of residual hydrocarbons or other materials left in the comminuted material after treatment, intermolecular forces between the flowable waste and the surface of the comminuted material, the wettability of the comminuted material relative to the flowable waste, capillary forces, the viscosity of the flowable waste, the surface tension of the flowable waste, the density of the flowable waste, temperature, and other factors that contribute to the reduction in surface energy. The retention capacity is at least partially controlled by the reduction in surface energy of the flowable waste when in contact with the body of comminuted material. Thus, the retention capacity may be a function of the properties of and the interaction between the body of comminuted material and the flowable waste material, e.g. the retention capacity of the body of comminuted material may be different for different waste materials. In general, the retention capacity can be the maximum amount of flowable waste material that can be stably retained within the comminuted material without waste material flowing out of the comminuted material or pooling at the bottom of the comminuted material under the force of gravity.

As used herein, "substantially stationary" refers to an almost stationary arrangement of flowable waste material within the comminuted material. This means that the flowable waste material has substantially no bulk flow, allows small scale flow (e.g., intra-pore flow, flow within a wetting film layer surrounding the comminuted material, random convection, or flow between adjacent particles of comminuted material). The substantially stationary flowable waste material may also be displaced if the comminuted material precipitates or settles in the encapsulation barrier. However, the substantially stationary flowable waste material does not bulk flow, flow out of the body of comminuted material or collect at the bottom of the comminuted material under the influence of gravity.

As used herein, "about" refers to a degree of deviation based on experimental error common to the particular property identified. The ranges provided by the term "about" will depend on the particular context and the particular property and can be readily discerned by one skilled in the art. The term "about" is not intended to detail or limit the equivalence, which may be given a specific value. Additionally, unless otherwise indicated, the term "about" shall expressly include "exactly" consistent with the discussion below regarding ranges and numerical data.

As used herein, "adjacent" refers to two structures or elements being in proximity. In particular, elements identified as "adjacent" may abut or be connected. Such elements may also be located near or proximate to each other, and not necessarily in contact with each other. In some cases, the exact proximity may depend on the particular circumstances.

Concentrations, dimensions, amounts, and other numerical data may be presented herein in a range format. It is to be understood that such range format is used merely for convenience and brevity and should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a range of about 1 to about 200 should be interpreted to include not only the explicitly recited endpoints of 1 and about 200, but also to include individual dimensions such as 2, 3, 4, and sub-ranges such as 10 to 50, 20 to 100, and the like.

As used herein, a plurality of items, structural elements, compositional elements, and/or materials may be presented in the same list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no single member of such list should be construed as a de facto equivalent of any other member of the same list solely based on their presentation in a common group without indications to the contrary.

Any steps recited in any method or process claims may be executed in any order and are not limited to the order presented in the claims. Device-plus-function or step-plus-function limitations are intended only to apply where, for a particular claim limitation, all of the following conditions are met: a) a "means for.. or a" step for.. is expressly recited; and b) followed by explicit recitation of the corresponding function. The structures, materials, or acts that support the means for adding functionality are expressly described in the description herein. The scope of the invention should, therefore, be determined only by the appended claims and their legal equivalents, rather than by the descriptions and examples given herein.

Long term storage of waste

Systems for long term storage of waste typically operate by retaining flowable waste material within a stationary body of comminuted material. The comminuted material can have a high surface area and can comprise particles of treated hydrocarbonaceous material from which hydrocarbon products have been derived. Waste material may be any flowable hazardous or non-hazardous material that is desired to be disposed of by long term storage. The comminuted material can have a retention capacity, which refers to the amount of flowable waste material that can remain substantially stationary within the comminuted material. The retention capacity may depend on a variety of factors, such as the surface area of the comminuted material, the porosity of the comminuted material, the intermolecular forces between the flowable waste material and the surface of the comminuted material, the viscosity of the flowable waste material, the surface tension of the flowable waste material, and the like. In general, the retention capacity may be the maximum amount of flowable waste material that can be stably retained within the comminuted material without waste material flowing out of the comminuted material or pooling in the bottom of the comminuted material under the influence of gravity. In addition, the encapsulation barrier may wrap the comminuted material. The encapsulation barrier can serve as an aid to prevent escape of waste material. In some embodiments, the encapsulation barrier may be completely impermeable to waste material. In other cases, the encapsulation barrier may be partially impermeable to the waste material. Generally, a partially impermeable barrier can reduce waste diffusion to less than 10%, in some cases less than 5%, and in other cases less than 1% of the diffusion without the barrier.

In view of the above, a system for long-term storage of waste may include a body of comminuted material surrounded by an encapsulation barrier. Referring to fig. 1, the system includes a comminuted material 100 surrounded by an encapsulation barrier 105. The comminuted material may be pieces of larger agglomerates rubblized or otherwise broken up, such as rubblized rock formations. The particles of comminuted material can have a variety of sizes and shapes. As shown in fig. 2, the particles 200 of the pulverized material may be irregularly shaped. Each particle has a longest dimension 205. The size of the particles may vary, but in some embodiments, the longest dimension of the majority of the particles by volume may be between about one millimeter (1mm) and about thirty centimeters (30 cm). The size and shape of the particles may depend on the design of the system and the method used to crush the comminuted material. In some embodiments, the particles may have a wide distribution of longest dimensions, such as a random distribution of longest dimensions between about one millimeter and about thirty centimeters. In other embodiments, the longest dimension may be more uniform. The surface area of the comminuted material can be influenced by the size and shape of the particles. For example, smaller particles may have a greater surface area than an equal volume of larger particles. As a general guideline, more than 90% of the particles may have a low aspect ratio of less than 5: 1, and in most cases less than 2: 1. Further, although not required, the particles may have a non-uniform shape, varying from particle to particle.

The comminuted material 100 can have a high surface area and can typically be very large in volume so that the system can retain a significant volume of waste. For example, a typical storage system may be formed to have more than about 1000m³To 160 km³The volume of (a). The size range of the system may be: a depth of about 10m to 200m, and a planar surface area of 0.5 to 5 acres.

The comminuted material can have a high surface area. The surface area of the comminuted material can contribute to the retention capacity of the comminuted material. For example, a high surface area may result in a greater magnitude of surface tension and capillary forces between the comminuted material and the waste material. The waste material may adhere to the surface of the comminuted material particles and thereby be retained in the body of comminuted material. As shown in fig. 2, the flowable waste material 210 may adhere to particles 200 of comminuted material. The flowable waste material may form a film 215 on the surface 220 of the particles and also collect in the interstices between the particles. The thickness of the film and thus the amount of waste material that can be retained depends on a number of factors, such as the surface tension, viscosity and density of the waste material, as well as the shape, surface area and wettability of the comminuted material with respect to the waste material. In some cases, the film may be a wet film, or in other words, a stable film resulting from the waste wetting the surface of the comminuted material. Waste material may also be retained in the interstitial spaces 225 between the particles.

The comminuted material can also be a generally porous material. The pores can increase the surface area of the comminuted material and can also increase retention capacity by absorbing waste material into the pores. As shown in fig. 2, particles 200 of comminuted material may have pores 230 with exposed openings at the particle surface 220. In some cases, the aperture may have an internal volume that completely fills the waste 210. Thus, the waste material may be absorbed into the particles of comminuted material. In other cases, the inner surface 235 of the hole may be wetted by the film 215 of waste material without the waste material filling the interior volume of the hole.

Both high surface area and high porosity may contribute to the retention capacity of the comminuted material. The retention capacity may be affected by a number of factors, including void space in the comminuted material, capillary forces, intermolecular forces, wettability of the comminuted material relative to the waste material, surface area of the comminuted material, porosity of the comminuted material, temperature, viscosity of the waste material, density of the waste material, and the like. The greater the retention capacity, the more waste material can be stored in the comminuted material. In some embodiments, the comminuted material can retain an amount of waste material equal to the retention capacity. In other embodiments, the comminuted material can contain an amount of waste material that is less than the retention capacity, such as within 20% of the retention capacity, in some cases within 10% of the retention capacity, and in other cases within 5% of the retention capacity. Storing an amount of waste material less than the retention capacity may provide a safety margin to ensure that waste material does not escape from the comminuted material. Since systems for long-term storage of waste can be designed to retain the waste for long periods of time, the use of safety margins can help prevent the possibility of loss of waste due to abnormal conditions or events. While the storage time may be determined by the particular application, the designed storage time may be at least 5 years, in some cases at least 20 years, and in other cases at least 100 years.

Although shredded materials can typically retain amounts of waste material up to a retention capacity, it is envisaged that waste material can escape if conditions change sufficiently, for example large temperature changes, weather changes (e.g. floods or heavy rain) or soil displacement beneath or around the shredded material or changes in the nature of the waste material. In these cases, the amount of storage less than the retention capacity may reduce the risk of escape of waste material. In some embodiments, the waste material is present in an amount less than about 90% of the comminuted material retention capacity. In other embodiments, the waste material is present in an amount less than about 70% of the comminuted material retention capacity, providing a wider safety margin. However, when swelling clays are used as barrier materials, changes in groundwater or hydration levels generally do not compromise the barrier properties of the system.

The comminuted material can include particles of treated hydrocarbonaceous material from which hydrocarbonaceous products have been derived. Spent hydrocarbonaceous materials can typically have very high surface areas. For example, oil shale is a hydrocarbon-rich rock that can become highly porous after removal of hydrocarbons. Untreated oil shale contains kerogen, organic material, bound to an inorganic matrix of mineral-rich material. Kerogen is found in thin layers and pits throughout oil shale. After removal of the kerogen by pyrolysis, an inorganic matrix having a network of pores previously at least partially occupied by the kerogen is left behind. In addition, the mechanical weakness formed in the oil shale during pyrolysis can form a network of cracks and voids, which further increases the porosity of the spent oil shale. In some embodiments, the hydrocarbonaceous material processed in the comminuted material can be waste oil shale, waste tar sands, coal residue, lignite residue, bitumen residue, or mixtures thereof. The treated hydrocarbonaceous material can be an undesirable residual product of a hydrocarbon extraction operation. Thus, the use of treated hydrocarbonaceous materials in a system for long-term storage of waste can provide a convenient way to dispose of both flowable waste and undesirable treated hydrocarbonaceous materials.

In some embodiments, the comminuted material can contain substantially only the treated hydrocarbonaceous material from which the hydrocarbonaceous product has been derived. However, in other embodiments, the comminuted material can comprise other optional materials. Low quality oil shale may be included in the comminuted material, for example, if the oil shale does not contain sufficient quantities of kerogen to make extraction profitable. In some embodiments, the comminuted material can comprise other raw soil materials, such as clay, compacted fill, refractory cement, expansive clay amended soil, compacted soil, low grade shale, and combinations thereof. However, the material of the untreated hydrocarbonaceous material most often can comprise less than 50% by volume, and in some cases less than 10% by volume, of the storage body comprising the treated hydrocarbonaceous material.

As previously discussed, flowable waste material may be retained in the comminuted material. As a flowable material, the waste material may be pumped or poured into the body of comminuted material. In some embodiments, the waste material may be a liquid. The liquid waste may be substantially only liquid or may contain solid particles to form a slurry or suspension. Furthermore, the liquid waste may comprise any type of liquid material. For example, the liquid waste may comprise substantially pure liquid chemicals, mixtures of chemicals, and dissolved solids and gases. In another alternative aspect, the flowable waste material may be a gas or flowable particles. An example of flowable waste particles may be calcined waste, or particulate fines generated as a by-product of a primary waste treatment process.

The flowable waste material is able to flow into the comminuted material, allowing the flowable waste material to form a wetted film, fill interstitial spaces, and be absorbed into pores in the comminuted material or otherwise adsorbed on the surface of the comminuted material. In some embodiments, the waste material may form a wetting film around the comminuted material. The wetting film is a stable film obtained by wetting the surface of the pulverized material with the waste material, and may have different thicknesses depending on the adhesion between the waste material and the pulverized material and other factors such as the surface tension of the waste material. As shown in fig. 2, the film 215 of the waste material 210 may substantially conform to the surface 220 of the particles 200 of comminuted material. The film thickness may vary from location to location depending on the geometry of the particles and the proximity of other particles. Alternatively, the films surrounding two adjacent particles may merge together and form a continuous region of waste material remaining between the particles. In some embodiments, the waste material may form a wetting film around at least a majority of the comminuted material by volume. Even thin wetting films can contain large volumes of waste material if they form a wetting film around a large portion of the high surface area comminuted material. In some cases, the waste material may fill interstitial spaces 225 between the particles, while in other cases, the interstitial spaces may contain a film of the waste material and empty void spaces. In addition, waste material may flow into the apertures 230 and fill the apertures, thereby being absorbed into the particles of comminuted material.

The waste material may be retained within the comminuted material such that the waste material is substantially stationary. If the waste material is present in an amount equal to or less than the retention capacity of the comminuted material, the waste material may be substantially stationary in that it will be in the form of a wetted film, trapped in interstitial spaces, or adsorbed in the pores of the comminuted material. Thus, the waste material may be present in an amount such that the waste material does not flow out of the body of comminuted material or collect at the bottom of the body of comminuted material under the influence of gravity. When the comminuted material and the barrier material are raw earth material or other natural material, the stability and retention of the retained waste material may be extended indefinitely. Thus, the retention system described herein can effectively retain flowable waste so long as catastrophic failure of the barrier is avoided.

By being stored in the system according to the invention, hazardous waste can be effectively disposed of. Disposal of hazardous waste can be challenging as it can cause injury to personnel and the environment. The system of the present invention retains hazardous waste for a long period of time and, in most cases, ensures indefinitely that the hazardous waste does not escape into the environment. Hazardous waste can typically include hazardous materials having one or more of the following characteristics, more than a modest amount: high flammability, high reactivity, corrosiveness, toxicity and radioactivity. The temperature of the system may also affect the stability or the degree of danger of some hazardous waste. Detailed definitions of these characteristics and lists of specific hazardous wastes have been published by the environmental protection agency. The hazardous waste suitable for storage using the present invention may include flowable hazardous waste material identified in 40 c.f.r.261 (7/1/2012), but other hazardous materials may also be stored. Other materials, such as radioactive materials, may also be hazardous waste. In some embodiments of the invention, the flowable waste material may be a hazardous material selected from: radioactive waste, chemical waste, pesticides, automotive waste, solvents, caustic, heavy metal-containing waste, refrigerants, biological waste, biohazardous materials, immobilized biological materials, and mixtures thereof. Specific non-limiting examples of hazardous materials may include mercury, arsenic, cadmium, and the like.

The flowable waste material may generally be material other than residual hydrocarbon products or other process residues, etc., that remain after the hydrocarbons are derived from the hydrocarbonaceous material. Although the goal of the hydrocarbon production process is to remove as much hydrocarbon from the hydrocarbonaceous material as possible, a certain amount of residual hydrocarbon can remain in the treated spent hydrocarbonaceous material. The residual amount of residual hydrocarbons may vary depending on various factors. For example, poor temperature control during the hydrocarbon production phase can result in less efficient hydrocarbon production, thus leaving more residual hydrocarbons. Even though these residual hydrocarbons are mobile in some cases and can be considered as waste since they are not recovered as useful products, they refer to residual recovered process materials and non-mobile waste materials in the present invention. Herein, the term flowable waste refers to waste added to the comminuted material regardless of the nature of the residual recycled process material present in the comminuted material prior to introduction of the flowable waste.

Metals and other chemicals in oil shale may be examples of residual recovery process materials left in the processed hydrocarbonaceous materials during hydrocarbon recovery. Some of these residual recovery process materials may be considered hazardous. The flowable waste of the present invention may be some other material than these remaining metals and chemicals. In general, the flowable waste material stored in the comminuted material can be a foreign substance that was not originally present in the hydrocarbonaceous material (i.e., not a component produced). For example, flowable waste material may be transported from a remote location to be stored in the comminuted material. Flowable waste materials may also be generated by on-site processes other than comminuting the body of material, such as on-site at a hydrocarbon refinery. Thus, the following materials are not considered flowable waste: materials such as produced hydrocarbon products, produced carbon dioxide or other products (including by-products) of the process are recovered. In one alternative, the comminuted material can be used to capture or store residue from the extraction process. Non-limiting examples of extraction processes may include cyanidation leaching in gold or copper extraction operations, extraction of uranium from waste shale, and the like. In these processes, the pulverized material may serve as an extraction space in which extraction processing is performed. Alternatively, the comminuted material may merely serve as a storage space for the residues from a spatially separate extraction process to be placed after extraction.

Residual recovery process materials, such as hydrocarbons, metals, and other chemicals remaining in the treated hydrocarbonaceous material, can affect the retention capacity of the comminuted material. The comminuted material may have a smaller exposed surface area because of, for example, the presence of adsorbed residual hydrocarbons. In some cases, residual hydrocarbons can plug pores and further reduce retention capacity. Conversely, such residual hydrocarbons, carbon, and other substances may increase the beneficial surface energy for capturing the flowable waste, and thus, may decrease the combined surface energy sufficient to improve the adhesion and retention capacity within the comminuted material. The above factors may be taken into account when determining the retention capacity of the comminuted material to avoid filling the comminuted material too full with flowable waste.

The comminuted material may be wrapped with an optional encapsulation barrier to provide a secondary barrier to the process of ejection of waste material from the system. The encapsulation barrier may include a bottom portion, a top portion, and sidewall portions connecting the bottom and top to form an enclosed volume containing the comminuted material and restricting fluid flow out of the encapsulation barrier. In some embodiments, the encapsulation barrier may have one or more fluid inlets and outlets. These fluid inlets and outlets may be used in the production of hydrocarbon products from hydrocarbonaceous materials within the encapsulation barrier and may also be used to introduce flowable waste into comminuted materials within the encapsulation barrier. The top portion defines an upper portion of the enclosed volume and is contiguous with the sidewall. The bottom also adjoins the side wall and may be substantially horizontal or inclined towards the discharge conduit as required for collecting hydrocarbon fluids extracted during the treatment of the hydrocarbon-containing material. The collection drain may be closed or blocked prior to introduction of the flowable waste material to prevent escape of the waste material.

In some embodiments, an encapsulation barrier may be formed along the walls of the excavated hydrocarbonaceous material deposit. For example, oil shale, tar sands, or coal may be mined from a deposit to form a cavity that approximately corresponds to the required packing volume for packing the barrier. The excavated cavity can then be used as a support for the encapsulation barrier. In an alternative embodiment, a guard may be formed around the outer wall surface of the encapsulation barrier if the encapsulation barrier is partially or substantially above ground level. The encapsulating barrier may be part of a free standing structure above ground with the berm supporting the sidewalls and the bottom of the barrier being supported by the ground below it.

The encapsulation barrier may be substantially free of undisturbed strata. In particular, the encapsulation barrier may be fully constructed and manmade as a separate isolation mechanism for preventing uncontrolled migration of waste material out of the comminuted material. The undisturbed formation may have fractures and pores that may allow the flowable waste material to penetrate through the formation. Forming the encapsulation barrier in a completely man-made structure without using the undisturbed formation as a bottom or wall can reduce the risk of the waste material seeping through the formation. However, in some embodiments, the encapsulation barrier may take some constituent of the surface of the excavated formation. For example, in some formations, the bottom and walls of the excavated excavation may have sufficiently low natural permeability that a significant barrier layer (e.g., a clay amended soil layer) may not be necessary for the barrier portion.

The package barrier may generally include a bottom, sidewalls extending upwardly from the bottom, and a top extending over the sidewalls to define an enclosed volume. Each of the bottom, side walls and top may be constructed of multiple layers including an inner layer of fine grain or other barrier material and an outer layer of swelling clay amended soil or similar fluid barrier material. Optionally, in addition to the swelling clay amended soil, an outer membrane that further prevents fluid flow out of the encapsulation barrier may be employed as a fluid barrier. The outer membrane may act as a secondary backup seal in the event that the primary seal fails for any reason. An inner layer of high temperature asphalt or other fluid barrier material may also optionally be applied to the inner surface of the particulate layer and define the inner surface of the encapsulation barrier.

Swelling clays are hydratable inorganic materials that cause the clay to swell or otherwise form a barrier to fluid flow. Encapsulation barriers may be formed from dry clay particles and other raw earth materials, and the clay may then be hydrated to swell the clay particles and form the barrier. Typically, such a barrier layer may be formed from solid phase particles and liquid phase water, which together form a substantially continuous fluid barrier. For example, swelling clay modified soil may be used to form the bottom, walls and top of the encapsulation barrier. When the swelling clay is hydrated, it will swell and fill the void spaces between the particles of other materials in the soil. In this way, the swelling clay modified soil becomes less permeable to flowable waste material inside the encapsulated barrier. By thoroughly mixing the swelling clay with other raw soil materials, the encapsulation barrier may be substantially impermeable to fluid flow. Some examples of suitable swelling clays include bentonite, montmorillonite, kaolinite, illite, chlorite, vermiculite, slate, smectite, and the like.

The combined layers form an encapsulation barrier that acts as a barrier to the comminuted material, thereby retaining heat within the enclosed volume to facilitate the removal of hydrocarbons from oil shale, tar sands, or other hydrocarbon-containing materials. The plasticity of the swelling clay amended soil layer seals the barrier, preventing waste material from leaking out of the barrier. The insulating properties of the fine particle layer are such that the temperature gradient across the layer allows the swelling clay amended soil layer to be sufficiently cool to retain moisture. This property prevents migration of hydrocarbons out of the barrier (except via designated conduits) during the formation of hydrocarbons from hydrocarbonaceous materials. This property also prevents the waste material from escaping out of the barrier after the flowable waste material is stored in the comminuted material. However, consistent with the description herein, it may be desirable to fill the comminuted material with flowable waste material at a volume below the retention capacity. In this way, in each zone, the phenomenon of the accumulation or local concentration of waste material exceeding the retention capacity of the material can be avoided, thus limiting or completely eliminating the reliance on such external secondary barriers.

In some cases, the isolating particulate layer may be omitted from the encapsulation barrier. For example, the insulating layer is optional if the comminuted material is subjected to an alternative process (e.g., solvent extraction or leaching) that does not require the application of heat or the generation of heat in order to remove matter therefrom. In such an embodiment, the soil layer amended with hydrated swelling clay seals the enclosed volume containing the comminuted material from the external environment. A suitable impermeable membrane may optionally line the inner surface of the hydrated swelling clay amended soil layer. While not always desirable, such an inner liner may prevent interaction between the hydrated swelling clay amended soil layer and solvents and/or leached fluids that may otherwise react with or damage the hydrated swelling clay amended soil layer.

In use, the insulating layer is most often formed from a fine-grained layer. Typically, the fine particle layer may be a particulate material having a diameter of less than 3 cm. The fine particle layer may typically be made of the following, although other materials may be suitable: gravel, sand, crushed lean shale, or other particulate fines that do not trap or otherwise inhibit fluid flow. By selecting the appropriate particle material and layer thickness, the fine particle layer can serve as the primary source of insulation and can maintain a substantial thermal gradient from the inner surface to the outer surface. The gas, while able to penetrate the permeable fine particle layer, is substantially unable to penetrate the encapsulating expandable clay layer. As is the case with the hydrocarbon extraction process, when the temperature of the comminuted material is above the temperature of the inner surface of the encapsulated layer of expandable clay, the gas may be sufficiently cooled (below the condensation point of the respective gas) in the fine particle layer and liquid may condense out of the gas. These liquids then drip through the granules to the bottom of the encapsulation barrier where they collect and are removed.

Any suitable method may be used to form the encapsulation barrier. However, in one aspect, the barrier is formed from the bottom up. The formation of the one or more walls and the filling of the package with the comminuted material may be accomplished simultaneously in a vertical deposition process that deposits the material in a predetermined pattern. For example, multiple chutes or other particle delivery mechanisms may be oriented along respective locations above the deposited material. By selectively controlling the volume of particles delivered, and the location along the overhead view of the system at which each individual granular material is delivered, layers and structures can be formed simultaneously from bottom to top. The sidewall portions of the barrier may be formed as continuous upward extensions at the outer periphery of the base and each layer present, including the swelling clay amended soil layer, the fine particle layer, and the film and/or asphalt liner (if present) are constructed as continuous extensions of the base counterpart. In the process of building the side wall, comminuted material can be placed simultaneously on the bottom and within the perimeter of the side wall, so that the filling of the volume to be enclosed is carried out simultaneously with the process of building the side wall up. In this manner, the formation of internal retaining walls or other lateral constraints can be avoided. This method may also be monitored during vertical stacking in order to verify that the blending occurring at the interface of the layers is within acceptable predetermined tolerances (e.g., to maintain the functionality of the layers). For example, excessive blending of swelling clay amended soil layers with fines may compromise the sealing function of the swelling clay amended soil layers. This excessive blending phenomenon can be avoided by carefully depositing each adjacent layer during construction, and/or by increasing the thickness of the deposited layer.

As the build process approaches the upper portion, the top can be formed using the same transport mechanism as described above, and only the deposition location and speed of the appropriate material to form the top layer need be adjusted. For example, when the desired height of the sidewalls is reached, a sufficient amount of encapsulation barrier material may be added to form the top.

Regardless of the particular method employed to form the encapsulation barrier, the base is generally formed first and the method may include placing an optional outer film, a swelling clay amended soil layer, and a fine grain layer. Optionally, an asphalt layer can be disposed adjacent to the inner surface of the fines layer. Depending on the particular installation, heating tubes, collection tubes, fluid delivery tubes, collection trays, and/or other structures may optionally be embedded in the deposited comminuted material. The barrier formed may also have a cover layer disposed on top. If a barrier is to be formed under an existing slope, a cavernous recess may be prepared by a digging step or other suitable step. If the barrier is not located in an underground location, soil or other support berms may surround the sidewalls and support the layer material as it is deposited.

With the above description in mind, fig. 1 shows a side view of one embodiment of the encapsulation barrier 105 surrounding the comminuted material 100. The existing surface or excavation ramp 110 is used primarily as a support for the bottom portion 115 of the barrier. The bottom portion includes an optional outer membrane 118, a swelling clay amended soil layer 120, an insulating fines layer 122, and optionally an inner bitumen layer 124. A continuous sidewall portion 130 is constructed upwardly from the bottom portion and includes an outer membrane 132, an expansive clay amended soil layer 134, a fine particle layer 136, and optionally an inner asphalt layer 138. As previously mentioned, as the barrier is built up, layers may be formed from bottom to top simultaneously. Additionally, as the walls are built, a comminuted material (e.g., oil shale, tar sands, coal, etc.) can be placed on the bottom and fill the enclosed volume to be formed. Depending on the placement of the system, the outer surfaces of the side wall sections and the bottom section may be supported by the guard or (if excavated) by the bottom and walls of the excavation. Each of the bottom portion, walls, and top portion 140 of the barrier collectively form an insulating containment layer. Generally, these portions of the layers are continuous layers surrounding the comminuted material.

After the sidewall portions 130 are constructed, either simultaneously or separately, the comminuted material 100 is placed within the enclosed volume to be formed. The roof 140 can be formed over the comminuted material and adjacent to the sidewall portions. As with the bottom and sidewalls, the top may have multiple layers, including an optional outer membrane 142, an expansive clay amended soil layer 144, a fines layer 146, and optionally an inner asphalt layer 148. The cover layer 150 may also cover the top if desired. In addition, the material used as the cover layer may be used as a sidewall or bottom to encase or surround the barrier.

The layers of the bottom, side walls and top are continuous and in direct contact or communication with similar materials such that, for example, the fine particle layers 122, 136 and 146 are one continuous layer surrounding the enclosed volume. The same applies to the outer membrane layers 118, 132 and 142, the swelling clay amended soil layers 120, 134 and 144, and the inner bitumen layers 124, 138 and 148 (if used). Notably, the thickness of each layer may not be uniform throughout the barrier. The thickness of each layer is not critical, as long as the layer thickness is functional for its intended purpose (e.g., insulation, fluid barrier, etc.), and the presence of the layer is of concern. Although the thickness of the encapsulation barrier may vary, suitable thicknesses may typically range from about 4cm to about 2 m.

A method of storing flowable waste material may include contacting a substantially stationary body of comminuted material with flowable waste material. The comminuted material can have a high surface area to allow the comminuted material to have a high retention capacity. The comminuted material can include particles of treated hydrocarbonaceous material from which hydrocarbonaceous products have been derived. The encapsulation barrier may wrap the comminuted material.

The types of materials used in the method and their characteristics and features may be the same as described above for the system for storing flowable waste. The comminuted material may be of the same particle size, surface area and material as described above. Similarly, the flowable waste material used in the method may include all of the flowable waste materials described above, including hazardous and non-hazardous waste. The encapsulation barrier may also have the same materials, construction and construction methods as described above.

In some embodiments, the step of contacting the substantially stationary body of comminuted material with the flowable waste material may comprise injecting the flowable waste material into the comminuted material. The injection operation may be performed by pumping waste material from the outside of the encapsulation barrier through the conduit to the inside of the encapsulation barrier. In some cases, the conduit may be the same as that used in the hydrocarbon production stage for injecting heating fluid or removing hydrocarbon products. In other embodiments, the step of contacting the comminuted material with the waste material may be performed in other ways. The waste material may be mixed with the comminuted material prior to introducing the comminuted material into the encapsulation barrier. In any event, the introduction of the flowable waste material may be performed so as to minimize local pooling or retention of the excess volume void waste material. Thus, the flowable waste material can be distributed throughout the comminuted material to increase homogeneity and to take advantage of the storage capacity of the overall body of comminuted material. This can be done using multiple dispensing inlets, existing embedded piping, and/or monitoring the flowable waste material at various locations. Generally, the introduction of waste material into the comminuted material can locally provide a large amount of waste material in excess of the retention capacity. Thus, once the local retention capacity is reached, excess flowable waste material will flow into the comminuted material in the lower region of the vicinity. Monitoring the waste level and/or modeling the total volumetric capacity can be used to determine the volume of flowable waste material that can be introduced into a given volume of comminuted material while not exceeding the retention capacity of the total volume.

The method may further comprise performing a hydrocarbon production stage to extract hydrocarbons from the comminuted material prior to the step of contacting the comminuted material with the flowable waste material. Fig. 3 illustrates an exemplary method 300 that includes extracting 310 hydrocarbons from hydrocarbonaceous materials within an encapsulation barrier and contacting a substantially stationary body of comminuted material with flowable waste material. As noted above, the comminuted material has a high surface area and comprises particles of treated hydrocarbonaceous material from which the hydrocarbonaceous product has been derived. The comminuted material is also wrapped 320 by an encapsulation barrier.

The foregoing detailed description has described the invention with reference to specific exemplary embodiments. However, it will be understood that various modifications and changes may be made without departing from the scope of the invention as set forth in the appended claims. The specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications or alterations (if any) are intended to fall within the scope of the invention as described and illustrated herein.

Claims

1. A system for long term storage of waste comprising:

a) a comminuted material having an average longest particle size of from about 1mm to about 30cm and a high surface area and a flowable liquid waste material that remains stationary within the interstitial spaces and in pores of the comminuted material for at least 5 years, the comminuted material comprising particles of treated hydrocarbonaceous material from which a product has been derived; and

b) an encapsulation barrier surrounding the comminuted material;

wherein the waste is not the product.

2. The system of claim 1, wherein the processed hydrocarbonaceous material is selected from spent oil shale, spent tar sands, coal residue, bitumen residue, or mixtures thereof.

3. The system of claim 2, wherein the coal residue is lignite residue.

4. The system of claim 1, wherein the encapsulation barrier comprises a raw earth material selected from the group consisting of: clay, cement, clay-modified soil, compacted soil, low-grade shale, or combinations thereof.

5. The system of claim 4, wherein the clay is a swelling clay.

6. The system of claim 5, wherein the swelling clay is selected from montmorillonite, kaolinite, illite, chlorite, or vermiculite.

7. The system of claim 4, wherein the clay-modified soil is bentonite.

8. The system of claim 4, wherein the compacted earth is compacted fill.

9. The system of claim 4, wherein the cement is a refractory cement.

10. The system of claim 1, wherein the encapsulation barrier is a free-standing or undisturbed formation.

11. The system of claim 1, wherein the flowable waste material comprises a material selected from the group consisting of: radioactive waste, pesticides, automotive waste, solvents, caustic, refrigerants, biological waste, extraction residues, and mixtures thereof.

12. The system of claim 11, wherein the biowaste is biohazardous waste.

13. The system of claim 1, wherein the flowable waste material comprises heavy metal-containing waste.

14. The system of claim 1, wherein the flowable waste material comprises chemical waste.

15. The system of claim 1, wherein the waste material forms a wetting film around the comminuted material.

16. The system of claim 1, wherein the waste material is present in an amount equal to or less than a retention capacity of the comminuted material.

17. The system of claim 1, wherein the comminuted material further comprises a raw soil material selected from the group consisting of: clay, cement, expansive clay modified soil, compacted soil, low grade shale, or combinations thereof.

18. The system of claim 17, wherein the compacted earth is compacted fill.

19. The system of claim 17, wherein the cement is a refractory cement.

20. A method for storing flowable waste comprising contacting a substantially stationary body of comminuted material with flowable liquid waste, the comminuted material having an average longest particle size of from about 1mm to about 30cm and a high surface area, the comminuted material comprising treated particles of hydrocarbonaceous material from which hydrocarbon products have been derived, the comminuted material being surrounded by an encapsulation barrier and the flowable liquid waste being stored within pores of the comminuted material and interstitial spaces within the comminuted material, and allowing the flowable liquid waste to remain stationary in the pores and interstitial spaces for at least 5 years.

21. The method of claim 20, wherein the treated hydrocarbonaceous material is selected from spent oil shale, spent tar sands, coal residue, bitumen residue, or mixtures thereof.

22. The method of claim 21, wherein the coal residue is lignite residue.

23. The method of claim 20, wherein the encapsulation barrier comprises a raw earth material selected from the group consisting of: clay, cement, clay-modified soil, compacted soil, low-grade shale, or combinations thereof.

24. The method of claim 23, wherein the clay is a swelling clay.

25. The method of claim 24, wherein the swelling clay is selected from montmorillonite, kaolinite, illite, chlorite, or vermiculite.

26. The method of claim 23, wherein the clay-modified clay is bentonite.

27. The method of claim 23, wherein the compacted earth is compacted fill.

28. The method of claim 23, wherein the cement is a refractory cement.

29. The method of claim 20, wherein the waste material is a hazardous material.

30. The method of claim 20, wherein the waste material forms a wetting film around the comminuted material.

31. The method of claim 20, wherein the waste material is present in an amount equal to or less than a retention capacity of the comminuted material.

32. The method of claim 20, wherein contacting comprises injecting the waste material into the comminuted material.

33. The method of claim 20, further comprising extracting hydrocarbon products from hydrocarbonaceous materials within the encapsulation barrier prior to contacting the comminuted material with the waste material, wherein a retention capacity of the hydrocarbonaceous materials is increased during the extracting.

34. The method of claim 20, wherein the comminuted material is contacted with the flowable waste material after the comminuted material has been wrapped by the encapsulation barrier.